IANA assigns port 6063 to x11: X Window System.
sudo ss -tlnp 'sport = :6063'sudo ss -ulnp 'sport = :6063'sudo lsof -nP -i :6063sudo netstat -tlnp | grep ':6063 'netstat -ano | findstr :6063Get-NetTCPConnection -LocalPort 6063 -State Listen | Select LocalAddress,OwningProcessnc -vz -w 5 HOST 6063Test-NetConnection HOST -Port 6063nc -vzu -w 5 HOST 6063sudo ufw deny 6063/tcpsudo iptables -A INPUT -p tcp --dport 6063 -j DROPsudo nft add rule inet filter input tcp dport 6063 dropNew-NetFirewallRule -DisplayName 'Block TCP 6063' -Direction Inbound -Protocol TCP -LocalPort 6063 -Action Blocksudo ufw deny 6063/udpsudo iptables -A INPUT -p udp --dport 6063 -j DROPsudo nft add rule inet filter input udp dport 6063 dropNew-NetFirewallRule -DisplayName 'Block UDP 6063' -Direction Inbound -Protocol UDP -LocalPort 6063 -Action BlockAll port numbers · Open port checker
Assignment data: IANA port number registry (public domain), retrieved 2026-11-10.